Allogene Therapeutics Publishes Preclinical Data in Clinical Cancer Research Supporting DLL3 as a Potential AlloCAR T™ Target for Small Cell Lung Cancer

• Preclinical Efficacy and Safety Results Indicate AlloCAR T™ Development Candidate Controls Tumor Growth without Off-Tumor/Normal Tissue Toxicity

SOUTH SAN FRANCISCO, Calif., Jan. 25, 2023 (GLOBE NEWSWIRE) — Allogene Therapeutics, Inc. (Nasdaq: ALLO), a clinical-stage biotechnology company pioneering the development of allogeneic CAR T (AlloCAR T™) products for cancer, today announced the publication of a preclinical study demonstrating delta-like ligand 3 (DLL3) is a promising tumor target for AlloCAR T™ in small cell lung cancer (SCLC). The findings were published in Clinical Cancer Research, a journal of the American Association for Cancer Research (AACR).

SCLC is an aggressive disease with limited treatment options. Approximately 30,000 patients in the United States are affected each year with this disease which has a 5-year overall survival rate of approximately 7%.¹ DLL3, with high expression on tumors and limited expression in normal tissue, is a promising target for SCLC and potentially other solid tumors.

“As a leader in allogeneic CAR T research and development, we are committed to exploring the potential of this therapeutic modality across a broad range of indications, including in solid tumors where there is significant need,” said Barbra Sasu, Ph.D., Chief Scientific Officer at Allogene.

This study describes the selection of ALLO-213 as an allogeneic CAR T development candidate targeting DLL3 from a large number of single chain variable fragment (scFv)-based anti-DLL3 CAR candidates. The selection of ALLO-213 was based on potency and specificity against SCLC cell lines in vitro and in vivo, including cell lines with very low antigen density to establish sensitivity. The results from the pre-clinical study showed:

• No DLL3 on target toxicity was observed in preclinical models supporting a potentially attractive safety profile
• Clinical DLL3 CAR candidates controlled DLL3+ tumor growth in mice without normal tissue toxicity

About Allogene Therapeutics
Allogene Therapeutics, with headquarters in South San Francisco, is a clinical-stage biotechnology company pioneering the development of allogeneic chimeric antigen receptor T cell (AlloCAR T™) products for cancer. Led by a management team with significant experience in cell therapy, Allogene is developing a pipeline of “off-the-shelf” CAR T cell candidates with the goal of delivering readily available cell therapy on-demand, more reliably, and at greater scale to more patients. For more information, please visit www.allogene.com and follow @AllogeneTx on Twitter and LinkedIn.

Cautionary Note on Forward-Looking Statements
This press release contains forward-looking statements for purposes of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. The press release may, in some cases, use terms such as “predicts,” “believes,” “potential,” “proposed,” “continue,” “estimates,” “anticipates,” “expects,” “plans,” “intends,” “may,” “could,” “might,” “will,” “should” or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. Forward-looking statements include statements regarding intentions, beliefs, projections, outlook, analyses or current expectations concerning, among other things: the ability to further research and develop ALLO-213 or any other anti-DLL3 AlloCAR T candidate; and the potential benefits of any anti-DLL3 AlloCAR T candidate or any other AlloCAR T candidate. Various factors may cause differences between Allogene’s expectations and actual results as discussed in greater detail in Allogene’s filings with the SEC, including without limitation in its Form 8-K filed on November 29, 2022 and under the “Risk Factors” heading of its Form 10-Q for the quarter ended September 30, 2022. Any forward-looking statements that are made in this press release speak only as of the date of this press release. Allogene assumes no obligation to update the forward-looking statements whether as a result of new information, future events or otherwise, after the date of this press release.

AlloCAR T™ is a trademark of Allogene Therapeutics, Inc.

Allogene’s AlloCAR T™ programs utilize Cellectis technologies. The anti-DLL3 AlloCAR T programs are licensed exclusively from Cellectis by Allogene and Allogene holds global development and commercial rights to these AlloCAR T programs.

Allogene Media/Investor Contact:
Christine Cassiano
Chief Communications Officer
(714) 552-0326
Christine.Cassiano@allogene.com

^{1Lung cancer – small cell – statistics. Cancer.Net. (2023, January 6). Retrieved January 24, 2023, from https://www.cancer.net/cancer-types/lung-cancer-smallcell/statistics#:~:text=Lung%20cancer%20is%20the%20second,be%20diagnosed%20with%20lung%20cancer}